Art of straightening vehicle frames



Sept. 5, 1961 A. H. LUEDICKE, JR., ETAL ART OF smucmsmuc VEHICLE FRAMES Filed May 20. 1959 QN fl N I 1 H M rinlil A f N Y RN NW.

INVENTOR$ 'H H. 4020 1 E, R

14 K. cHnP/mQ/v ATTOENEYf United States Patent 2,998,837 ART OF STRAIGHTENING VEHICLE FRAMES Alex H. Luedicke, Jr., Milwaukee, and William R. Chapman, Waukesha, Wis., assignors to Applied Power Industries, Inc., a corporation of Wisconsin Filed May 20, 1959, Ser. No. 814,428

7 Claims. (Cl. 153-32) The present invention relates generally to improvements in the art of straightening structural elements, and relates more particularly to improvements in the construction and operation of vehicle frame straighteners and a method of straightening frames.

In vehicle frame straightening work, the repairman are generally confronted with five basic types of frame damage, namely, vertical distortion or sag, side sway or lateral distortion, twist, siderails which are longitudinally displaced or out of square, and kick-up or sharp bends in the siderails. While several straightening tools have been heretofore proposed which are adapted to correct one or more of such types of damage, no single tool thus far commercially available is capable of effectively repairing all five of the basic types of damage.

Furthermore, it is also essential that frame straightening apparatus for work on damaged vehicles be of a portable nature and readily adjustable for convenience in properly manipulating the tool and applying the same to the damaged frame for most effectively performing the necessary restoring work. While some of the presently commercially available frame straighteners are portable or semi-portable, they do not possess the desired degree of adjustability and flexibility of application.

In addition, the frame straightening devices heretofore proposed have for the most part been unduly bulky and diflicult to store and manipulate, and some of these devices require the use of expensive lifting equipment, special costly; adapters, and considerable manpower in their application and use.

It is therefore an important object of the present invention to provide an improved vehicle frame straightening device which obviates all of the above-mentioned disadvantages and objections to prior frame straightening devices. I

Another object of the invention is to provide improved instrumentalities for effectively correcting vehicle frame damages of all types in a rapid and highly efficient manner and at relatively low cost.

Still another object of our invention is to provide an proved vehicle frame straightening device which is extremely portable, relatively compact, readily adjustable, and highly flexible in its adaptations, and which is capable of manipulation and use by a single operator.

An additional object of the present invention is to provide an improved method of and apparatus for removing or correcting twist damage to vehicle frames.

These and other objects and advantages of the invention will become apparent from the following detailed description.

A clear conception of the several features constituting the present improvement and of the mode of applying and utilizing the apparatus, as well as the method of correcting twist damage, may be had by referring to the drawings accompanying and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views.

FIG. 1 is a fragmentary side view of one of our improved frame straightening devices in assembled condition for storage, parts being broken away to reveal normally hidden structure;

FIG. 2 is a fragmentary top view of the frame straightener with the twist correcting beam removed and with the end post swung to vertical position;

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. 2 FIG. 3 is a transverse section through the device; take along the line 3-3 of FIG. 1; 3

FIG. 4 is a fragmentary side view of the extensible end section of the straightening device showing the end post in vertical position and with part of the extensible beam broken away for the sake of clarity;

FIG. 5 is a fragmentary section through the extensible beam taken along the line 5-5 of FIG. 4.

While the present invention has been shown and described herein as being especially applicable in straightening vehicle frames of a particular type having one form of damage, it should be understood that the use'of the improved device is not thereby unnecessarily restricted since it is equally adaptable to the correction of any known types of frames having one or more forms of damage, and the device is also well adapted to the repair of unit bodies which are difficult to manipulate with prior frame straighteners. It is also contemplated that the broadest possible interpretation shall be given to various descriptive terms used herein, and the use of the term frame throughout this specification and the appended claims is intended to apply either to a structural frame member as such or to that part of a unitized body corresponding to the frame.

Referring to the drawings and particularly FIGS. 1 to 5 thereof, the improved frame straightening device shown therein as embodying a twist correction beam which is the essential feature of our copending application Serial No. 94,397, filed March 8, 1961, comprises, in general, a tubular main beam 10, a beam extension 11 adapted to telescope within one end of the beam 10 and extensible to various positions of adjustment, a pivot arm 12 secured to the other end of the main beam 10, a hook 13 slidable longitudinally to different positions of adjustment along the pivot arm 12, a hydraulic power actuator 14 secured between the beam 10 and pivot arm 12, a post 15 secured to the exposed end of the extensible beam 11 and adapted to be swung. from an inactive horizontal position to vertical position, and a twist correctingbeam 16 detachably secured to the main beam 10 as by means of a U-bolt 17 and clamp 18. j,

The main beam 10 is supported by a pair of floorengaging wheels 20 while the extensible member is provided with a floor-engaging caster 21 to thus render the device readily portable and capable of proper positioning by a single operator. To accommodate frames of different types and sizes and to permit adjustment for the performance of various types of work, the telescopic beam extension may be readily extended to desired positions, and upon adjustment, a lock pin 22 may be inserted through alined holes 23, 24 in the beams 10, 11 respectively to maintain the beams in extended condition.

The post 15 is pivotally secured medially thereof between the side walls of the extensible beam 11 by means of a pivot pin 25, the upper and lower walls of the tubular beam 11 being cut away to permit the post 15 to be readily swung from horizontal inactive position as shown in FIG. 1 to the vertical position shown in FIGS. 2, 4 and 5, and when in vertical position, the post 15 bears against a transverse edge 26 of the upper run of the beam 11 which is reinforced by a bearing plate 27 secured to the beam as by welding or the like, the post 15 also being provided with a plurality of holes 28 for selectively receiving a locking pin 29 cooperable with the bottom of the beam 11 to positively retain the post in its vertical position while permitting vertical adjustment thereof.

The pivot arm 12 is secured to the beam 10 by means of a pair of lower flange plates 31 forming a bifurcated member extending on opposite sides of the beam and secured to the beam or to suitable side plates 32 thereof by a pivot pin 33 to permit swinging movement of the arm 12, and it will be noted that the swinging movement of the arm 12 is limited by the edge 31' of the bifurcated member which thus provides a safety stop, preventing pivotal movement of the arm beyond a predetermined distance as illustrated by the dot-and-dash line in FIG. 1 in the event of rupture or breakage of a force transmitting element attached between the arm 12 and a workpiece. The power actuator 14 may be in the nature of a fluid motor, the head or cylinder end of which is pivotally attached to a bracket or upstanding flange 34 on the beam and the piston or plunger 35 of which is pivotally attached to a bracket or flange 36 on the arm 12. The motor or power actuator 14 is of conventional type, either single or double acting, and the cylinder thereof is connected by a fluid conduit to a suitable pump for furnishing pressure fluid thereto to extend the piston 35 and thus swing the arm 12. The arm 12 is also provided with hook 13 swingably carried by a strap 37 slidably embracing the arm-12, the strap 37 having suitable slide shoes 38 secured thereto and provided with set screws 39 for securing the hook assembly in any desired position of adjustment along the arm 12.

The twist correcting beam 16 may be conveniently secured to the main beam 10 in approximately longitudinal alignment therewith by means of the U-bolt 17 and clamping bracket 18 when the device is stored or inactive. When the device is used for correcting sag, side sway, longitudinal siderail displacement, or sharp siderail bends, the beam 16 may be readily removed in an obvious manner by merely dismantling the bolt 17 and clamp 18. However, when it is desired to correct a frame which is twisted, the bolt 17 is loosened and the beam 16 is swung relative to the beam 10 to provide an X-shaped tool when viewed from above, the bolt 17 and clamp 18 then again being tightened.

In straightening damaged vehicle frames, the main idea is to reverse the blow that caused the damage in the first instance so that the metal returns to its normal shape. It is therefore necessary to first determine the type of damage requiring correction, and this is done with the aid of commercially available frame gages and dimension charts. After the type of damage has been determined, the improved frame straightener should be so applied to the damaged frame so as to pull the bent parts under applied pressure along substantially the same line of impact or initial bending force until the frame is restored to its original position. If several types of damage have been caused and require correction, these should be repaired one at a time, and it is generally best to start with repairs that pull the damaged parts.

In repairing sag with the improved device, the main beam 10 is placed under the bent frame rail in approximate longitudinal alignment therewith. A hydraulic jack or the like is then positioned between the beam 10 and the bent frame rail at the center of the sag area and the beam 10 is chained to the bent frame rail at opposite ends of the bend. Pressure is then applied through the jack until the frame rail is back in alignment, and each of the bent rails should be operated upon independently.

For repairing side sway, the beam 10 is first positioned below and transversely of the frame and the ends of one of the frame siderails outwardly beyond the bent portion are chained to the post which has been swung to vertical position. The pivot arm 12 is then chained through its hook 13 to the medial portion of the sag or bend area in the other frame siderail, and the arm 12 is swung under pressure by the fluid motor or ram 14 until the frame siderails are back in alignment, the arm 12 exerting a pulling force on the frame as it is actuated.

To correct longitudinal displacement of the frame siderails, the improved device is used in much the same manner as for side sway correction. In such case, the vertical post 15 is chained to one of the frame siderails at a corner of the frame, and the pivot arm 12 is chained to the other siderail at a diagonally opposed corner of the frame. The arm 12 is then swung about its pivot by means of the power actuator 14, thus pulling the siderails in opposite directions until they are restored to normal corrected position.

To repair siderail kick-up or sharp bends, the improved straightening device is positioned longitudinally under the central portion of the frame with the vertical post 15 bearing against a medial portion of the end cross-rail of the frame. The pivot arm 12 is then chained to the other end of each frame siderail, and a pulling force is exerted by swinging the arm 12 by means of the actuator 14 until the bends are eliminated. In this application as well as in correcting longitudinal displacement of the frame siderails, it is frequently necessary to extend the beam 11.

It is apparent that both the force-applying arm 12 and the force-resisting or reaction arm or post 15 are swingable in the same plane corresponding to the longitudinal plane or axis of the beam 10. It is also apparent that the caster or wheel 21 not only cooperates with the wheels 20 to facilitate transportation of the device, but also maintains the end of the beam 10 and/ or beam extension 11 out of contact with the ground to provide clearance for the post 15 when swung to vertical position as shown in FIG. 4.

It should be understood that it is not desired to limit this invention to the exact details of construction of the improved device or to the precise steps of the frame correction method herein shown and described, since various modifications within the scope of the appended claims will occur to persons skilled in the art to which this invention pertains.

We claim:

1. A vehicle frame straightening device comprising. a generally horizontal main beam, and a generally upright force-applying arm attachable through a force transmitting element to a workpiece and pivotally secured to one end of said beam for swinging movement in a plane corresponding to the longitudinal axis of said beam, said arm having a stop cooperable with said beam for limiting swinging movement thereof in the event of rupture of said element.

2. A vehicle frame straightening device according to claim 1, in which the means for pivotally securing the arm to the beam consists of a bifurcated member, the cross-piece of which provides the limit stop.

3. A vehicle frame straightening device according to claim 1, wherein a post cooperable with another part of the workpiece is pivotally secured to said beam remote from said force applying arm for swinging movement in the same plane from a position substantially parallel to said beam to a position extending upwardly therefrom.

4. A vehicle frame straightening device according to claim 3, wherein thrust absorbing bearing means are provided for said post on opposite sides of its pivot when said post is in its upright position.

5. A vehicle frame straightening device comprising, a generally horizontal tubular beam, a generally upright force applying arm pivotally secured to one end of said beam, a power actuator pivotally connected between said beam and said arm to swing said arm under pressure, the top and bottom walls of said beam at the opposite end having vertically alined openings, a post pivotally secured medially thereof between the side walls of said beam for swinging movement within the space defined by said top and bottom wall openings from a position substantially parallel to said beam to a position extending upwardly therefrom, and a ground engaging wheel secured to the end of said beam adjacent said top and bottom openings spacing said beam end from the ground to provide clearance for said post when swung to its upright position.

6. A vehicle frame straightening device according to claim 5, wherein thrust absorbing bearing means are provided for said post on said beam adjacent the top and bottom wall openings thereof for definitely positioning said post when in upright position.

7. A vehicle frame straightening device according to claim 5, wherein ground engaging transporting wheels also support the beam intermediate the ends thereof and substantially at the center of gravity of the device.

References Cited in the file of this patent UNITED STATES PATENTS 6 Harrison Mar. 24, 1942 Johnston June 1,1948 Jacobsen et al. Apr. 3, 1951 Elam May 20, 1952 Harteker Apr. 14, 1953 Ferguson July 21, 1953 Smith Sept. 27, 1955 Rodgers June 19, 1956 Johnson Aug. 7, 1956 Pertner May 27, 1958 FOREIGN PATENTS Australia Dec. 15, 1944 

